Common rail fuel systems in which the fuel is delivered into a fuel rail by a pumping unit are known from the market. Multiple fuel injection devices are connected thereto, which inject the fuel directly into combustion chambers assigned thereto. The pressure in the fuel rail is detected by a pressure sensor and regulated to a variable setpoint pressure by a setting unit. The fuel quantity injected into a combustion chamber is a function on the one hand of the instantaneous actual pressure in the fuel rail and on the other hand, of the activation period and the injection period of the fuel injection devices related thereto.
The signal provided by the pressure sensor may be flawed due to damage, intentional manipulation, or pronounced drift, which has the result that the real pressure prevailing in the fuel rail deviates from the setpoint pressure more than desired. The durability of components of the fuel system may thus be reduced, the mixture formation quality may decrease, and deviations of the actual injection quantity from a setpoint injection quantity may result. The latter plays an important role in the field of engine tuning, in particular.